Method of forming an inlaid pattern in an asphalt surface

ABSTRACT

This application relates to a method of forming an inlaid pattern in an asphalt surface. The pattern may be selected for functional or decorative purposes. In one embodiment the method comprises the steps of providing a first template having a predetermined pattern; impressing the first template into the asphalt surface when the asphalt surface is in a pliable state to form an impression therein; removing the first template from the asphalt surface to expose the impression; providing a second template having a predetermined pattern matching the pattern of the first template; inserting the second template into the impression; and fixing the second template in position within the impression to form the inlaid pattern. The second template may consist of a preformed thermoplastic grid having a color and/or texture contrasting with the asphalt surface. In another embodiment the second template may include a light source for illuminating the template after it has been fixed in position.

TECHNICAL FIELD

[0001] This application relates to a method of forming an inlaid patternin an asphalt surface. The pattern may be selected for functional ordecorative purposes.

BACKGROUND

[0002] Various methods for forming patterns in asphalt surfaces areknown in the prior art. The Applicant is the owner of U.S. Pat. No.5,215,402 which describes a method of forming a pattern in an asphaltsurface using a removable template. The template is compressed into apliable asphalt surface to imprint a predetermined pattern simulating,for example, the appearance of bricks, cobblestones, interlocking pavingstones or the like. The template is then lifted clear of the asphaltsurface and the asphalt is allowed to harden. A thin layer of acementitious coating may be applied to the imprinted asphalt to enhancethe brick and mortar or other desired effect.

[0003] In the above-described method the template does not remain inlaidwithin the asphalt surface. The visual effect is created by thecombination of the imprinted pattern and the decorative coating. Onedrawback to this method is that the decorative coating may wear off overtime, particularly in high traffic areas.

[0004] It is known in the prior art to install traffic markings onasphalt surfaces. However, such markings typically project above theasphalt surface and are relatively bulky. In regions receiving frequentsnowfalls during the winter months traffic markings may be removed ordamaged by snowplow usage.

[0005] Another known method for producing traffic markings involvesgrinding grooves in asphalt surfaces and then pouring into the grooves ahot molten material which is allowed to set in place. However, this is avery time consuming procedure and is not well suited for formingcomplicated patterns or covering large surface areas.

[0006] The need has therefore arisen for improved methods and materialsfor inlaying patterns in asphalt surfaces.

SUMMARY OF INVENTION

[0007] In accordance with the invention, a method of forming an inlaidpattern in an asphalt surface is disclosed. The method includes thesteps of:

[0008] (a) providing a first template having a predetermined pattern;

[0009] (b) impressing the first template into the asphalt surface whenthe asphalt surface is in a pliable state to form an impression therein;

[0010] (c) removing the first template from the asphalt surface toexpose the impression;

[0011] (d) providing a second template having a predetermined patternmatching the pattern of the first template;

[0012] (e) inserting the second template into the impression; and

[0013] (f) fixing the second template in position within the impressionto form the inlaid pattern.

[0014] The method may include the step of heating the asphalt surfaceprior to impressing the first template into the asphalt surface.

[0015] The step of fixing the second template in position within theimpression comprises heating the second template to cause the secondtemplate to bond to the asphalt surface. For example, the secondtemplate may be heated to a temperature within the range of about 150°F.-350° F.

[0016] The second template may comprise a pre-formed thermoplastic gridof unitary construction. The color of the grid may be selected tocontrast with the color of the asphalt surface. In another embodimentthe grid may include a light source for lighting the grid once it hasbeen set in place in the asphalt surface. In other embodiments the gridmay be luminescent or flourescent, such as when subjected to light of asuitable wavelength.

[0017] In one embodiment the second template may comprise an uppersurface which is substantially flush with the surface of the asphaltwhen the second template is fixed in position. Alternatively, a portionof the second template may be raised above the asphalt surface orrecessed below the asphalt surface when it is set in place.

[0018] The second template may be formed from a plurality of frameelements each having a relatively narrow width to facilitate compressionof the template into the asphalt surface without the need to applysubstantial compactive force. For example, the frame elements may have awidth between ¼ inch and 1 inch.

[0019] In a further alternative embodiment the template may becompressed into the asphalt surface directly while the asphalt surfaceis in a pliable state and without deforming the desired predeterminedpattern. The template is then fixed in place as in the embodimentdescribed above.

BRIEF DESCRIPTION OF DRAWINGS

[0020] In drawings which illustrate embodiments of the invention, butwhich should not be construed as restricting the spirit or scope of theinvention in any way,

[0021]FIG. 1(a) is a perspective view of a portable heater forpreheating an asphalt surface;

[0022]FIG. 1(b) is a perspective view of a first template defining apredetermined pattern for imprinting an asphalt surface;

[0023]FIG. 1(c) is a perspective view of the first template beingforcefully compressed into the asphalt surface using a compactionapparatus;

[0024]FIG. 1(d) is a perspective view of the first template being liftedclear of the asphalt surface to expose an impression having thepredetermined pattern;

[0025]FIG. 1(e) is a perspective view of a second template having apattern matching the pattern of the first template and showing thesecond template being lowered into the impression formed in the asphaltsurface;

[0026]FIG. 1(f) is a perspective view of a portable heater forre-heating the asphalt surface to fix the second template in positionwithin the impression;

[0027]FIG. 2(a) is a perspective view of a portable heater forpreheating an asphalt surface as in FIG. 1(a);

[0028]FIG. 2(b) is a perspective view of a template defining apredetermined pattern and suitable for direct compression into theasphalt surface;

[0029]FIG. 2(c) is a perspective view of the template of FIG. 2(b) beingforcefully compressed into the asphalt surface using a compactionapparatus without deforming the predetermined pattern;

[0030]FIG. 2(d) is a perspective view of a portable heater forre-heating the asphalt surface to fix the second template in position;

[0031]FIG. 3 is a perspective view of a template of FIGS. 1 and 2;

[0032]FIG. 4(a) is a diagrammatic side elevational view of the method ofFIG. 2 wherein the template is delivered from a spool mounted on avehicle having a drum roller; and

[0033]FIG. 4(b) is a plan elevational view of the method of FIG. 4(a).

DESCRIPTION

[0034] Throughout the following description, specific details are setforth in order to provide a more thorough understanding of theinvention. However, the invention may be practiced without theseparticulars. In other instances, well known elements have not been shownor described in detail to avoid unnecessarily obscuring the invention.Accordingly, the specification and drawings are to be regarded in anillustrative, rather than a restrictive, sense.

[0035] With reference to the drawings, this application relates tomethods and apparatus for imprinting an asphalt surface 10. As used inthis patent application “asphalt” means a paving compound forconstructing roads, driveways, walkways and the like which consists of acombination of bituminous binder, such as tar, and an aggregate, such assand or gravel.

[0036] As shown in FIG. 1(b), a first template 12 is provided forimprinting a predetermined pattern in asphalt surface 10. Thepredetermined pattern may serve a specific function, such as a crosswalkmarking, or it may be purely decorative. In the illustrated embodimentfirst template 12 comprises a flexible grid defining a plurality of openareas (FIG. 3). However, it should be appreciated that the structure offirst template 12 may vary without departing from the invention. Forexample, template 12 may have a flat, continuous top surface and aplurality of projections formed on its bottom surface arranged in thedesired pattern.

[0037] Template 12 is compressed into asphalt surface 10 when surface 10is in a pliable state. For example, template 12 may be compressed intohot, freshly rolled asphalt (which is typically on the order of150°-400° F. depending upon the type of ashpalt). Alternatively, aportable surface heater 14 may be provided (FIG. 1(a)) for preheating apreexisting asphalt surface 10 to a pliable state. Template 12 may becompressed into surface 10 with a mechanical compactor, such as avibrating plate compactor 16 or a drum roller.

[0038] After template 12 has been compressed into asphalt surface 10(FIG. 1(c)) it is removed to expose an impression 18 in the desiredpattern (FIG. 1(d)). For example, impression 18 may consist of aplurality of channels or simulated grout lines. By way of anotherexample, impression 18 may be the outline of a corporate logo ordecorative design.

[0039] The next step in the process is to provide a second template 20configured to fit within impression 18. As shown in FIG. 1(e)), secondtemplate 20 preferably has a shape and layout matching at least partlythe pattern of first template 12. In one embodiment of the inventionsecond template 20 may match the pattern of first template 12 (and henceimpression 18) exactly. In an alternative embodiment of the invention,second template 20 may partially but not completely match the pattern offirst template 12. In this case second template 20 partially fillsimpression 18 when it is inlaid within asphalt surface 10.

[0040] Second template 20 is positioned within impression 18 as shown inFIG. 1(e). In one embodiment of the invention second template 20 mayconsist of a preformed grid formed from a thermoplastic material. Asuitable thermoplastic material is available from Lafarge Road Markingsand is sold under the trademark THERMALINE™. Rubber, plastic or othermaterials suitable for inlaying in asphalt surface 10 could alsooptionally be employed. Template 20 may have a color and/or texturedesigned to contrast with asphalt surface 10. In one possiblearrangement the depth of template 20 is less than or equal to the depthof impression 18 so that template 20 does not extend above the plane ofasphalt surface 10 when it is inlaid in position. In another possiblearrangement, the depth of template 20 exceeds that of impression 18 sothat template 20 is raised above the plane of asphalt surface 10 whenset in position. In this latter arrangement template 20 is both visuallyand tactilely distinguishable from asphalt surface 10. This may beuseful, for example, in regulating the speed of vehicles traversing apaved roadway or the like.

[0041] In one embodiment of the invention templates 12 and 20 are formedfrom a plurality of frame elements 13 which are relatively narrow inwidth and are arranged in a grid (FIG. 3). This ensures that suchtemplates can be readily compressed into asphalt surface 10 without theneed to apply substantial compactive force. Also, in high traffic areas,frame elements 13 of relatively narrow width are less subject to wear.For example, frame elements 13 may have a width less than the width of astandard automobile tire. A width size between ¼ inch and 1 inch issuitable for most applications. Ordinarily frame elements 13 will not beless than ¼ inch in width to ensure that they are readily visible oncetemplate 20 is fixed in position (although they may be some applicationswhere very narrow frame elements 13 could be employed).

[0042] The final step in the installation procedure is to fix secondtemplate 20 in position within impression 18. In the embodimentillustrated in FIG. 1(f), portable surface heater 14 is passed over thesurface of second template 20 after it has been positioned withinimpression 18 to reheat surface 10. If template 20 is formed from athermoplastic material as described above, this causes template 20 toflow into the interstices of impression 18 thereby enhancing adhesion toasphalt surface 10. Once template 20 is fully seated within impression18, heater 14 is removed and template 20 is allowed to set in place.Alternatively template 20 may be pre-heated prior to its placementwithin impression 18 to facilitate template seating. Depending upon thematerial used, the second template 20 may be pre-heated or heated insitu to a temperature within the range of 100°-400° F., o r moreparticularly 150°-350° F.

[0043] Another possible means for fixing template 20 within impression18 is by the use of conventional glue adhesives. For example, impression18 could be coated with a glue adhesive prior to the placement oftemplate 20 therein. The step of fixing template 20 in position couldtherefore include applying the glue and allowing the glue sufficienttime to set. Alternatively template 20 may comprise a tear-off layerwhich may be removed on site to expose an adhesive surface capable ofbonding to asphalt surface 10.

[0044] In one possible embodiment of the invention, template 20 mayconsist of reflective material suitable for designating pedestriancrosswalks, turning lanes and the like. In another embodiment template20 may include a light source for illuminating template 20 in its inlaidposition, such as for safety or decorative purposes. Similarly, template20 may be formed from flourescent material or material which isluminescent when subjected to light of a suitable wavelength (such asultraviolet light). In another embodiment template 20 may be constructedfrom a skid-resistant material.

[0045] In an alternative embodiment of the invention shown in FIG. 2second template 20 may be compressed directly into asphalt surface 10without first forming an impression 18 using first template 12. In orderfor this alternative method to work effectively asphalt surface 10 mustbe sufficiently pliable such that template 20 will not deform from thedesired pattern when it is compressed into surface 10. As in theembodiment discussed above, surface 10 may be preheated to a pliablestate (FIG. 2(a). As shown in FIGS. 2(b) and 2(c), template 20 is thencompressed directly into surface 10. Surface 10 is then reheated aftertemplate 20 is in position to fix template 20 in place (FIG. 2(d)).

[0046] FIGS. 4(a) and 4(b) illustrate apparatus useful for carrying outthe alternative method of the invention described above in an automatedfashion. In the illustrated embodiment first template 20 is sufficientlyflexible that it may be wound around a spool 22 mounted on a vehicle 24.Vehicle 24 also includes a drum roller 26 for progressively compressingtemplate 20 into asphalt surface 10 as template 20 is unwound from spool22. Portable surface heaters 14 move in advance of and behind vehicle 24to pre-heat and re-heat the asphalt surface.

[0047] As will be apparent to those skilled in the art in the light ofthe foregoing disclosure, many alterations and modifications arepossible in the practice of this invention without departing from thespirit or scope thereof. Accordingly, the scope of the invention is tobe construed in accordance with the substance defined by the followingclaims.

What is claimed is:
 1. A method of forming an inlaid pattern in anasphalt surface comprising: (a) providing a first template having apredetermined pattern; (b) impressing said first template into saidasphalt surface when said asphalt surface is in a pliable state to forman impression therein; (c) removing said first template from saidasphalt surface to expose said impression: (d) providing a secondtemplate having a predetermined pattern at least partially matching thepattern of said first template; (e) inserting said second template intosaid impression; and (f) fixing said second template in position withinsaid impression to form said inlaid pattern.
 2. The method as defined inclaim 1, further comprising the step of heating said asphalt surfaceprior to impressing said first template into said asphalt surface. 3.The method as defined in claim 1, wherein the step of fixing said secondtemplate in position within said impression comprises heating saidsecond template to cause said second template to bond to said asphaltsurface.
 4. The method as defined in claim 3, wherein said secondtemplate is heated to a temperature within the range of approximately100°-400° F.
 5. The method as defined in claim 3, wherein said secondtemplate is heated to a temperature within the range of approximately150°-350° F.
 6. The method as defined in claim 1, wherein said secondtemplate comprises a pre-formed thermoplastic grid.
 7. The method asdefined in claim 1, wherein said second template is of unitaryconstruction.
 8. The method as defined in claim 1, wherein said secondtemplate has a color contrasting with the color of said asphalt.
 9. Themethod as defined in claim 1, wherein said second template comprises alight source for illuminating said second template after said templateis fixed in position within said impression.
 10. The method as definedin claim 1, wherein said second template is luminescent.
 11. The methodas defined in claim 1, wherein said second template is flourescent. 12.The method as defined in claim 1, wherein said second template comprisesan upper surface, wherein said upper surface is substantially flush withthe surface of said asphalt when said second template is fixed inposition.
 12. The method as defined in claim 1, wherein said secondtemplate comprises an upper surface, wherein said upper surface isrecessed below the surface of said asphalt when said second template isfixed in position.
 13. The method as defined in claim 1, wherein saidsecond template comprises an upper surface, wherein said upper surfaceprojects above the surface of said asphalt when said second template isfixed in position.
 14. The method as defined in claim 1, wherein secondtemplate comprises a grid formed from a plurality of frame elements,wherein said frame elements have a width less than 12 inches.
 15. Themethod as defined in claim 14, wherein said frame elements have a widthbetween ¼ inch and 1 inch.
 16. A method of forming an inlaid pattern inan asphalt surface comprising: (a) providing a template having apredetermined pattern; (b) impressing said template into said asphaltsurface when said asphalt surface is in a pliable state; and (f) fixingsaid template in position to form said inlaid pattern.
 17. The method ofclaim 16 wherein said template is formed from a plastic material. 18.The method of claim 17, wherein said template is formed from athermoplastic material.
 19. The method of claim 16, wherein saidtemplate is formed from rubber.
 20. The method as defined in claim 16,wherein said second template is of unitary construction.
 21. The methodas defined in claim 16, wherein said template has a color contrastingwith the color of said asphalt.
 22. The method as defined in claim 16,wherein said template comprises a light source for illuminating saidtemplate after it has been fixed in position within said asphaltsurface.
 23. The method as defined in claim 16, wherein said template isluminescent.
 24. The method as defined in claim 16, wherein saidtemplate is flourescent.
 25. The method as defined in claim 16, whereinsaid template comprises an upper surface, wherein said upper surface issubstantially flush with the surface of said asphalt when said secondtemplate is fixed in position.
 26. The method as defined in claim 16,wherein said template comprises an upper surface, wherein said uppersurface is recessed below the surface of said asphalt when said templateis fixed in position.
 27. The method as defined in claim 16, whereinsaid template comprises an upper surface, wherein said upper surfaceprojects above the surface of said asphalt when said template is fixedin position.
 28. The method as defined in claim 16, wherein templatecomprises a grid formed from a plurality of frame elements, wherein saidframe elements have a width less than 12 inches.
 29. The method asdefined in claim 28, wherein said frame elements have a width between ¼inch and 1 inch.